Open standard, reference Python implementation, and machine-checkable conformance suite for substrate-alignment primitives in multi-entity agent systems.
substrate-alignment is a behavioural-layer standard for systems in which multiple entities — humans, services, AI agents — cooperate and adversarially interact. It defines a small, auditable set of primitives that any conforming implementation must satisfy: gates, classifiers, audit-chain types, drift signals, halt-and-escalate protocols, pair-coupling integrity checks.
The project lets you make verifiable alignment claims about a multi-agent system, rather than asking reviewers to trust closed-source assertions.
pip install substrate-alignment # zero runtime dependenciesfrom substrate import (
DefaultNetPotentialGainGate, EntityRef,
InMemorySubstrateMetadataStore, RaiseOnNegativeGate,
)
store = InMemorySubstrateMetadataStore() # ships with the package; swap for your backend
gate = RaiseOnNegativeGate(inner=DefaultNetPotentialGainGate(metadata_store=store))
# Seed an affected entity, then route a consequential decision through the gate.
gate.evaluate_or_raise(
actor=EntityRef("agent", "alice"),
action_kind="teach",
affected_entities=[EntityRef("user", "bob")],
proposed_outcome={"expected_delta_by_entity": {"bob": 0.3}},
)If the proposed action would have negative net effect on the affected entities, the gate raises NetPotentialGainNegative carrying the per-entity contributions for audit.
substrate-conformance --probes conformance/probes/ # run the bundled probes
# 22/22 probes passed (0 required failures, 0 advisory failures).| Directory | What it contains | Audience |
|---|---|---|
spec/ |
Six normative specifications — the standard itself. | Implementers in any language; auditors; standards bodies. |
conformance/ |
22 machine-checkable behavioural probes that any implementation can run. | Vendors validating conformance; reviewers verifying claims. |
python/ |
Reference Python implementation. pip install substrate-alignment. |
Python application authors; the witness for the specification. |
Future language bindings (rust/, go/, ts/) will land as sibling top-level directories in this same repository.
- AI-safety researchers who want to make verifiable claims about multi-agent system behaviour.
- Regulated-industry platform builders (healthcare, finance, defence, sovereign cloud) whose alignment claims must survive procurement and audit review.
- Standards bodies and auditors evaluating vendor alignment claims against a published reference.
- Multi-agent system architects implementing cooperation primitives across services and teams.
Pre-release. The Python reference implementation has been extracted from the System9 platform, where these primitives are in production use. The first tagged release will be v0.1.0.
What is in place today on main:
- 6 normative specification documents under
spec/. - 22 YAML conformance probes under
conformance/probes/, all passing against the Python reference. - 136 source modules and 137 test modules under
python/; 2315 tests passing, pyright strict 0/0/0, pylint 10.00/10. - 10 engineering concept docs at
docs/concepts/covering every primitive category. - 4 framework adoption recipes at
docs/adoption/(FastAPI, Redis, Celery, SQLAlchemy). - 6 runnable examples at
python/examples/. - An anonymised production case study at
docs/case-studies/system9.md.
The CHANGELOG tracks released changes; the Unreleased section reflects what is in flight on main.
Host application
│
▼
┌────────────────────────────────────────────────────────────────┐
│ substrate (your decision surface routes through these) │
│ │
│ AlignmentRefresher ──┐ │
│ │ writes via │
│ NetPotentialGainGate ─┼──► SubstrateMetadataStore (Protocol) │
│ │ reads from │
│ DriftPatternMatcher ─┘ │
│ │ │
│ ▼ │
│ HaltAndEscalateProtocol ◄── SubstrateTraceLedger │
│ │
│ ResistanceBand ──► derive_threshold / derive_quota_pair / … │
│ PairCouplingStateMachine ──► extraction_monitor / … │
└────────────────────────────────────────────────────────────────┘
│
▼
Your persistent storage (implement SubstrateMetadataStore)
The host application supplies the storage backend (any implementation of SubstrateMetadataStore); every primitive consumes it through that one Protocol.
git clone https://github.com/System9ai/substrate-alignment.git
cd substrate-alignment/python
python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"
pytest # 2315 passing
pyright src/substrate tests # strict, 0/0/0
pylint src/substrate tests # 10.00/10
substrate-conformance --probes ../conformance/probes/ # 22/22
for f in examples/0*.py; do python "$f"; donesubstrate-alignment/
├── LICENSE Apache-2.0
├── README.md this file
├── CHANGELOG.md Keep-a-Changelog history
├── CONTRIBUTING.md contributor rules + PR checklist
├── CODE_OF_CONDUCT.md Contributor Covenant 2.1
├── SECURITY.md vulnerability-reporting policy
├── spec/ six normative specifications
├── conformance/ YAML probe runner + 22 probes
├── docs/ concepts, adoption guides, case study
└── python/ reference implementation
├── pyproject.toml
├── src/substrate/
├── tests/
└── examples/
- Specifications —
spec/: six normative documents covering operating-mode classification, the NPG gate Protocol, drift signals, runaway-power-prevention mechanisms, the four-options matrix, and conformance criteria. - Conformance —
conformance/: YAML probe runner with a documented schema, 22 bundled probes covering every spec, vendor-attestation guidance. - Concepts —
docs/concepts/: engineering rationale for each primitive (10 documents). Read these to understand why each primitive is shaped the way it is. - Adoption —
docs/adoption/: framework integration recipes (FastAPI permission gate, Redis-backed rate limiter, Celery task gate, SQLAlchemy metadata-store implementation). - Case study —
docs/case-studies/system9.md: anonymised production-deployment narrative.
See CONTRIBUTING.md. The hard rule: source code uses engineering vocabulary only; substrate-mathematical reasoning belongs in docs/concepts/ and spec/. This is what lets substrate-alignment withstand procurement and audit review.
substrate-alignment ships primitives used in safety-relevant code (the net-potential-gain gate, the halt-and-escalate protocol, the audit chain). Vulnerabilities in these primitives have downstream safety consequences. Report them privately per SECURITY.md.
Apache-2.0. See LICENSE.
A formal citation will accompany the first preprint. Until then, cite the repository:
@misc{substrate-alignment,
author = {System9},
title = {substrate-alignment: open standard for substrate-alignment primitives in multi-entity agent systems},
year = {2026},
url = {https://github.com/System9ai/substrate-alignment}
}